Bottom Line:
Despite the fact that BI effects do impact performance on everyday life activities, up to now it is still not clear whether the BI represents an amodal and material-independent process or whether it interacts with the task material.Results showed that individuals with WS exhibited a normal BI effect during verbal task-switching, but a clear deficit during visuo-spatial task-switching.Overall, our findings demonstrating that the BI is a material-specific process have important implications for theoretical models of cognitive control and its architecture.

Affiliation: Department of Psychology, University "Sapienza" of Rome, Rome, Italy.

ABSTRACTEffective task switching is supported by the inhibition of the just executed task, so that potential interference from previously executed tasks is adaptively counteracted. This inhibitory mechanism, named Backward Inhibition (BI), has been inferred from the finding that switching back to a recently executed task (A-B-A task sequence) is harder than switching back to a less recently executed task (C-B-A task sequence). Despite the fact that BI effects do impact performance on everyday life activities, up to now it is still not clear whether the BI represents an amodal and material-independent process or whether it interacts with the task material. To address this issue, a group of individuals with Williams syndrome (WS) characterized by specific difficulties in maintaining and processing visuo-spatial, but not verbal, information, and a mental age- and gender-matched group of typically developing (TD) children were subjected to three task-switching experiments requiring verbal or visuo-spatial material to be processed. Results showed that individuals with WS exhibited a normal BI effect during verbal task-switching, but a clear deficit during visuo-spatial task-switching. Overall, our findings demonstrating that the BI is a material-specific process have important implications for theoretical models of cognitive control and its architecture.

pone.0142613.g005: Visuo-Spatial Task-Switching in an ecological environment.Schematic representation of the visuo-spatial task-switching paradigm in an ecological environment (Experiment 3).

Mentions:
The large-scale radial arm maze (RAM) comprised a round central platform (3 m in diameter) with 8 arms (80 cm wide x 11 m long), radiating like the spokes of a wheel. White and red ribbons formed a barrier that marked the sides of each arm and forced the participants to return to the center of the starting platform before entering another arm, thus preventing them from “cutting corners.” At the end of each arm lay an orange plastic bucket (18 cm wide x 28 cm high) that contained a reward (a plastic coin). The 8 arms were virtually numbered as in Fig 5. The RAM was placed outdoors in a large square and was surrounded by extra-maze cues (e.g., trees, buildings, pavement, streetlamps) that were fixed throughout the experiment. Attention was paid to control the intra- and extra-maze environment with regard to cues, the location of the buckets, and the position of the experimenter. Participants could see and access the maze only during the experimental sessions.

pone.0142613.g005: Visuo-Spatial Task-Switching in an ecological environment.Schematic representation of the visuo-spatial task-switching paradigm in an ecological environment (Experiment 3).

Mentions:
The large-scale radial arm maze (RAM) comprised a round central platform (3 m in diameter) with 8 arms (80 cm wide x 11 m long), radiating like the spokes of a wheel. White and red ribbons formed a barrier that marked the sides of each arm and forced the participants to return to the center of the starting platform before entering another arm, thus preventing them from “cutting corners.” At the end of each arm lay an orange plastic bucket (18 cm wide x 28 cm high) that contained a reward (a plastic coin). The 8 arms were virtually numbered as in Fig 5. The RAM was placed outdoors in a large square and was surrounded by extra-maze cues (e.g., trees, buildings, pavement, streetlamps) that were fixed throughout the experiment. Attention was paid to control the intra- and extra-maze environment with regard to cues, the location of the buckets, and the position of the experimenter. Participants could see and access the maze only during the experimental sessions.

Bottom Line:
Despite the fact that BI effects do impact performance on everyday life activities, up to now it is still not clear whether the BI represents an amodal and material-independent process or whether it interacts with the task material.Results showed that individuals with WS exhibited a normal BI effect during verbal task-switching, but a clear deficit during visuo-spatial task-switching.Overall, our findings demonstrating that the BI is a material-specific process have important implications for theoretical models of cognitive control and its architecture.

Affiliation:
Department of Psychology, University "Sapienza" of Rome, Rome, Italy.

ABSTRACTEffective task switching is supported by the inhibition of the just executed task, so that potential interference from previously executed tasks is adaptively counteracted. This inhibitory mechanism, named Backward Inhibition (BI), has been inferred from the finding that switching back to a recently executed task (A-B-A task sequence) is harder than switching back to a less recently executed task (C-B-A task sequence). Despite the fact that BI effects do impact performance on everyday life activities, up to now it is still not clear whether the BI represents an amodal and material-independent process or whether it interacts with the task material. To address this issue, a group of individuals with Williams syndrome (WS) characterized by specific difficulties in maintaining and processing visuo-spatial, but not verbal, information, and a mental age- and gender-matched group of typically developing (TD) children were subjected to three task-switching experiments requiring verbal or visuo-spatial material to be processed. Results showed that individuals with WS exhibited a normal BI effect during verbal task-switching, but a clear deficit during visuo-spatial task-switching. Overall, our findings demonstrating that the BI is a material-specific process have important implications for theoretical models of cognitive control and its architecture.